Home » » Geography - World & Indian (Earth - A quick look): Page -2

Geography - World & Indian (Earth - A quick look): Page -2

Written By STPORTAL on Sunday, March 18, 2012 | 2:58 PM

Geography - World & Indian (Earth - A quick look):
Page -2
Structure of the Interior of Earth
Earth has a diameter of 12,756 km (7,972 mi). The Earths interior consists of rock and metal. It is made up of four main layers:

1) the inner core: a solid metal core made up of nickel and iron (1200 km diameter)

2) the outer core: a liquid molten core of nickel and iron

3) the mantle: dense and mostly solid silicate rock

4) the crust: thin silicate rock material

The temperature in the core is hotter than the Suns surface. This intense heat from the inner core causes material in the outer core and mantle to move around.

The movement of material deep within the Earth may cause large plates made of the crust and upper mantle to move slowly over the Earths surface. It is also possible that the movements generate the Earths magnetic field, called the magnetosphere

The core
The inner part of the earth is the core. This part of the earth is about 1,800 miles (2,900 km) below the earths surface. The core is a dense ball of the elements iron and nickel. It is divided into two layers, the inner core and the outer core. The inner core - the center of earth - is solid and about 780 miles (1,250 km) thick. The outer core is so hot that the metal is always molten, but the inner core pressures are so great that it cannot melt, even though temperatures there reach 6700ºF (3700ºC). The outer core is about 1370 miles (2,200 km) thick. Because the earth rotates, the outer core spins around the inner core and that causes the earths magnetism.

The Mantle
The layer above the core is the mantle. It begins about 6 miles(10 km) below the oceanic crust and about 19 miles(30 km) below the continental crust (see The Crust). The mantle is to divide into the inner mantle and the outer mantle. It is about 1,800 miles(2,900 km) thick and makes up nearly 80 percent of the Earths total volume.

The Crust
The crust lays above the mantle and is the earths hard outer shell, the surface on which we are living. In relation with the other layers the crust is much thinner. It floats upon the softer, denser mantle. The crust is made up of solid material but these material is not everywhere the same. There is an Oceanic crust and a Continental crust. The first one is about 4-7 miles (6-11 km) thick and consists of heavy rocks, like basalt. The Continental crust is thicker than the Oceanic crust, about 19 miles(30 km) thick. It is mainly made up of light material, like granite
Share this article :


Post a Comment

Support : Creating Website | Johny Template | Mas Template
Copyright © 2011. ST-PORTAL - All Rights Reserved
Template Created by Creating Website Published by Mas Template
Proudly powered by Premium Blogger Template